Police are investigating her on fraud and breach of trust charges after the former caretaker of her official residence made claims she had told him to inflate the number of guests at dinners and to record their purpose as state instead of private in order to receive more money for them.

She has denied the charges.

Avi Hadad, the owner of the company which conducted the test, said that, "upon examination of the test, we did not find in Mrs. Netanyahu's answers to the relevant questions any physiological responses which would indicate she is lying."

Mrs Netanyahu is a divisive figure, and has been described as "one of the most unpopular people in Israel".

The results of private lie detector tests are not admissible in Israeli courts because they are not believed to be reliable.

The news of the test came amid reports on Israeli television that the attorney general was expected to indict her by September 10.

Yossi Cohen, her lawyer, told Israeli public radio that the decision to take the test was taken, "following the horrible mudslinging against her and after we heard that she is going to be put on trial".

The first relates to suspicion he received illegal gifts from wealthy supporters, and the second alleges that he attempted to improperly arrange favorable coverage from a daily newspaper in exchange for legislation that would have hurt its competitor.

He has been questioned in relation to both the cases. Close associates of his are also implicated in two other corruption investigations, though Mr Netanyahu is not directly suspected in them.

The scandals resulting from accusations against him and his inner circle have raised questions about his political survival.

He denies all allegations of wrongdoing, and is not required to stand down unless convicted.